WordPress post image to show not the featured image

Question

I have a site in WordPress, and I want to display the WordPress post first image which is displayed in the post but remember not the featured images. so how to show it in the post and i want my post like below this is how blog design should be

This is the code

<div class="col-md-3 small-post-img">
 <a href="<?php the_permalink() ?>">
  <?php the_post_thumbnail(); ?>
 </a>
</div>

It not taking the the_post_thumbnail code because there is no any featured image in the post, but I have added the images in the inside post content. I want that post images as featured image.

Answer 1

Put this in your theme's functions.php file

function ash_post_first_img($post_content){
    preg_match_all('/<img[^>]+>/i', $post_content, $content_all_images);
    preg_match_all('/src="([^"]+)"/i', $content_all_images[0][0], $content_image);
    if (isset($content_image[1][0])) {
        return $content_image[1][0];    
    } else{
        return 'http://example.com/defaultimage.jpg';
    }
}

and use this function ash_post_first_img(get_the_content('')); where you want to display image's url "single.php or post.php"

<div class="col-md-3 small-post-img">
    <a href="<?php the_permalink() ?>">
        <img src="<?php echo ash_post_first_img(get_the_content('')); ?>">
    </a>
</div>

Change " http://example.com/defaultimage.jpg " to the default image url if no image is found.